Thioglycolic amide couplers



Patented Sept. 7, 1948 UNITED STATES THIOGLYGOLIC AMIDE GOUPLERAS ArnoldWeissberger,

Charles J. Kibler,

and

Richard V. Young, Rochester, N. Y., assignors to Eastman Kodak Company,Rochester, N. Y., a corporation of New Jersey No Drawing. ApplicationJune 10, 1944, Serial No. 539,780

19 Claims.

This invention relates to photographic colorforming or couplingcompounds and particularly to coupler compounds which are non-diffusingwhen incorporated in sensitive emulsion layers.

In Peterson U. S. Patent 2,296,306, granted September 22, 1942, and U.S. Patent 2,353,754, granted July 18, 1944, there are described couplerswhich contain a heterocyclic ring and a free imino or mercapto groupwhich is capable of forming a metallic salt in photographic emulsions.These compounds are quite non-diffusing in photographic emulsions butcombine with the development product of primary aromatic aminodeveloping agents to form colored images in the well known manner. Uponfixing, the metallic atom attached to the imino or mercapto group isremoved. and the unused coupler may be washed from the layer. Some ofthe couplers previously used are not, however, readily washed from theemulsion layer after fixing and tend to decompose and discolor the finalimage.

It is, therefore, an object of the present invention to provide a newclass of coupler compounds from which insoluble metallic salts may beformed in the emulsion layer. A further object is to provide couplercompounds which are readily soluble in the fixing bath and which may bereadily removed from the emulsion layer. Other objects will appear fromthe following description of our invention.

These objects are accomplished by incorporating in the emulsion layer athioglycolic amide derivative of a, coupler having the followingprobable formula:

where R and R'=hydrogen or alkyl groups, and M=a heavy metal.

These insoluble couplers are produced from coupling compounds of thefollowing probable formula:

where R and R.'=hydrogen or alkyl groups and X=hydrogen or acetyl.

. These couplers are formed by introducing the thioglycolic amideportion of the molecule into any well known type of coupler compound,such Mannes and Godowsky U. S. Patents 2,039,730, 2,108,602,. and2,113,330 or Marines, Godowsky, and Peterson. U. S. Patents 2,115,394and 2,126,337. It .is to be understood that when we refer. tointroducing the thiogl-ycolic amide portion into developing agents toform colored images.

coupler compounds, we do not mean that the final compound is necessarilyformed by simple substitution starting with these two materials. Thefinal compound may be formed by any suitable reaction which results in acompound having a thioglycolic amide portion as described above and acoupling portion or portions containing at least one group capable ofreacting with the development product of the developing agent to form a10 dye image.

The coupler portion of the molecule indicated in the general formulasabovecontains the functional or reactive group common to couplercompounds which react with primary aromatic amino This functional orreactive group is usually a reactive methylene or reactive ethenol groupand may occur at various positions or more than a single position in thecoupler molecule. By reactive methylene, we mean a CH2 group which isreactive in the coupling process. This group is usually present betweentwo negative centers as, for example, in the groups:

COCHz-CO, -CO-CH1CN or oo-cnicfi N in a, ring system or chain compound.One or both of the hydrogen atoms of the methylene group may besubstituted by certain groups without destroying the chemical activityof the group.

By reactive ethenol, we mean the group:

This group occurs in the phenolic and naptholic have the followingstructure:

I R R where R, R and X are the same as in the iormula above, and thephenol nucleus may contain other substituents, as long as it isunsubstituted or contains a replaceable substituent, such as halogen, inthe position para to the hydroxyl group; or

the following structure:

as those described in Fisher U. S. Patent 1,055,155,

Y R R where R, R. and X are the same as in the formula above, and Y isan acyl group such as acetyl or lbenzoyl, or a cyan'o group.

QNHO o omen Z-hydroxy-thioglycollc anilide n: om-O-mro omsn2-hydroxy-4-methylthioglycolic anilide OHaOGNHCOCHaSHZ-hydroxy-4-methoxy-thioglyco1ic anilide CHa-QNHC 001128112-hydroxy-4-methyl-5-chloro-thioglyco1ic anilide NH O O 0 111811 012-l1ydroxy-3,fi-dichloro-4-methyl-thioglycolic anilide 1 CH3 CHNHCO21HSCOCH:

2-(a-acctylmercaptopropionamido)-4,fi-dichloro-o-methylphenol I CH: CHa

omgnnooo-sn 2-hydroxy+methyl-5'chl0ro-(a-dimcthylthioglycolic anilide)NH O 0 CH2SH 5- (thioacetylamino)-1-naphth0l G00 0320 ONHONHCOCHzSHw-Benzoylacctamino-p-thioglycolic anilide o OOHzGONH-Q NH O O 0 H1811w-Benzoylacetamino-m-thioglycclic anilide O0 oomoorrn-Qmnooomsooomw-Benzoylacetamino-p-acetylthioglycolic anilide O-COCHzC ONHQ NBCOOHzSCQCHs 1-phenyl-3-(thioglycolylamino)-5-pyrazolone orno ocrocONH-QNHC 0 cross 0 CH3 Acetoacetylamino-p-acety]thioglycolicanilide Thecoupler compounds used according to our invention are generallyincorporated in the emulsion layer by =first forming a solution of thesodium or other soluble salt of the coupler and then incorporated in asilver halide emulsion whereupon part of the silver of the silver halidereplaces the sodium to form the silver salt of the coupler. Other heavymetal salts such as gold, nickel, mercury, cadmium or tin may be formedbefore the coupler is incorporated in the silver halide emulsion. Silversalts are preferred, however, since a silver salt is ordinarily used inthe production of sensitive layers and common silver salts, such assilver chloride or silver bromide are suitable for the purpose of ourinvention. Other silver salts which may be used are silver ferricyanide,silver ortho phosphate, silver arsenate, silver oxalate, silver cyanateand silver citrate. In the case of the acetyl derivatives of thethioglycolic amides, it is possible that the reaction with the silverresults in the formation of a complex rather than a pure salt. Theformation of such additional complexes is suggested by P. PfeifierOrganische Molekulverbindungen (1922), pages 60, i, 153 and 289.

The non-diffusing metal salts made according to our invention may beincorporated in single or multi-layer gelatin emulsion coatings or inlayers of other colloidal materials such as cellulose esters or naturalor synthetic resins, and mixtures of the couplers may be used in asingle layer.

The couplers which we propose to use are made in general by condensinthioglycolic acid or acetyl thioglycolyl chloride with the appropriateamine. The methods used in the preparation of the specific examplesabove were as follows:

Compound 5 is prepared as follows:

In a 1-liter round-bottomed flask is placed 163 grams (0.715 mole) ofpurified 2-amino-4,6-dichloro-5-methylpheno1 hydrochloride. To thehydrochloride is added 210 grams (0.238 mole) of thioglycolic acid and109.5 grams (0.845 mole) (100 cc.) of quinoline. The mixture is stirredwell and the flask is immersed in the steam bath and covered with atowel. The heating is continued for 5 hours with shaking at intervals.The reaction mixture is a brown liquid with some undissolvedhydrochloride. The mixture is cooled to about 35 and then stirred into 1literof water; at first a liquid forms which rapidly changes to a massof soft lumps. The crude anilide is filtered, washed with 1 liter ofwater and'sucked almost dry on the filter. The product is then dried ina vacuum desiccator over the week-end. Yield of crude product is 145grams (76.0%) M. P. 130-134".

Purification The 145 grams of crude grey anilide is dissolved in 1200cc. of boiling benzene, filtered and the filtrate is chilled rapidly toabout The anilide crystallizes in small colorless crystals which arefiltered and washed on the filter with 150 cc. of cold (10) benzene. Theproduct. is then sucked dry on the filter. Recovery is 116 rams (80%) M.P. 138-139". V

The 116 grams of anilide is recrystallized a second time from 1200 cc.of boiled benzene, filtered and then chilled to 10. The crystals arefiltered and'wash-ed with. 150 cc. of cold benzene. Recovery is 109grams (91.5%) M. P. 138.5-139.5.

The third and final crystallization is carried out by dissolving the 109grams of anilide in 1300 cc. of boiled chloroform, filtering andchilling to 0. The product crystallizes in small crystals which arefiltered off and then washed with 200 cc. of ice-cold chloroform. Theproduct is sucked. dry on the filter. The anilide is placed in a vacuumdesiccator overnight. Recovery is 87 grams (80%) M. P. 139-140". Yieldof purified product is 46%.

Compounds 1, 2, 3, 4, 8 and 14 are prepared in a similar manner, usingthe corresponding amine in place of 2-amino-4,6-dichloro-5-methylphenolhydrochloride.

Compound 7 is prepared by a method similar to that used in thepreparation of compound 5, using the corresponding amine anda-mercaptoisobutyric acid (Billmann, Ann. 348, 129) instead ofthioglycoli-c acid. The free base of the amine is employed, rather thanthe hydrochloride, and no quinoline i necessary. 7

Compound 13 is prepared as follows:

. omcos-omoom NET-O0 0 onion onto o-s-omoonn-O-ooomon Twenty grams(0.125 mole) of p amino-w-cyanoacetophenone was dissolved in 300 cc. ofdioxane, at 50 in a 500 cc. Erlenmeyer flask. The solution wasfilteredand cooled to Synthetic quinoline (16.1 grams) (0.125 mole) wasthen added and then 19.1 grams (0.125v mole) of acetylthioglycolylchloride was added to the well stirred solution. The temperature risesquickly and a precipitate forms. This precipitate was stirredoccasionally over a period of about an hour. The materials were pouredinto a beaker and 300 cc. of water was added. The precipitate wasthoroughly washed with water and then with alcohol. Twenty-seven gramsof product was recrystallized from 1500 cc. of alcohol. The product wasdecolorized with Darco. The material was recrystallized a second time,the solution standing overnight in the refrigerator before filtering.Yield:

Acetylthioglycolic wcid CH3COC1+HSCH2COOH r CHzC'OSCHzCOOH-l- HCI In a500-cc. 3'-necked flask fitted with a condenser, stirrer, and droppingfunnel was placed 139 cc. (2 moles) of thioglycolic acid. Then 175 cc.(2.5 moles) of acetyl chloride was added through the. dropping. funnelto the stirred mixture at such a rate as to cause rapid, but not toovigorous, evolution of HCl. The mixture warms spontaneously. It wastransferred to a 500-cc. modified Cl'aisen flask with a 10-inch columnand distilled under reduced pressure. A forerun of about 50 grams B.P.15=50-100, was collected. Then the mixture was cooled slightly, andthe distillation continued using a high-vacuum. The fraction, B.P.2.5=-118, was collected as acetylthioglycolic acid. It amounted to-175 grams (65%). (See Ber. 46, 1913, 2105.)

Acetylthzoglycolyl chloride A 500-cc. 3-necked round-bottomed flaskfitted with a thermometer, stirrer, outlet'tube, and an addition funnelis charged with 102 grams (0.75 mole) of acetyl thioglycolic acid. Theflask is immersed in a water bath maintained at about 20 as 93 cc. (1.27moles) of thionyl chloride is added dropwise to the stirred solution atsuch a rate as to cause evolution of HCl and S02 and to keep thetemperature of the reaction mixture at 25-30". After about 30% of thethionyl chloride is added, the vigor of the reaction subsidesconsiderably so that the remainder may be added rapidly. The mixture isstirred overnight at room temperature. The excess thionyl chloride isremoved at reduced pressure; heating the flask gently by means of awater bath which is gradually warmed from 25-65. Then 50 cc. of drybenzene is added; this is removed at reduced pressure. After repeatingthis process once more, the water bath is gradually warmed to 100 as thelast traces of benzene and thionyl chloride are removed. Finally theproduct is distilled through a short column using two water pumps totake care-of decomposition at the initial part of the distillation. Thefraction boiling at 98- 101 under 16-18 mm. is collected as pureacetylthioglycolyl chloride. The yield is 73 grams (64%). (Ber. 46,2105.)

Compounds 11. and 12 are prepared by condensingp-(benzoyla-cetamino)-ani1ine or m- (benzoylacetamino)-aniline withacetylthioglycolyl chloride in a. manner similar to that used in thepreparation of compound 13. m-(Benzoylacetamino)-aniline is. prepared asfollows, and p-(benzoylacetamino) -aniline is similarly prepared, usingethyl acetate as a solvent instead of alcohol:

Twenty-five grams of w-benzoyl-m-nitroacetanilide, suspended in 200 cc.of alcohol, is shaken in an atmosphere of hydrogen and in the presenceof Raney nickel at a temperature of 80-90 until the theoretical amountof hydrogen is absorbed. The catalyst is filtered off and the solutionis concentrated in va-cuo to 25 cc. Thus 13.5 grams ofm-(benzoylacetamino)-aniline melting at 156 is obtained.

w-Benzoyl-m-nitroacetanilide CaHsC O CHaC 010211! HzN N01 Forty-fivegrams of ethyl benzoylacetate, in an open beaker, is heated on an oilbath to 170-180". Then 22 grams of m-nitroaniline is added in smallincrements during 15 minutes, always allowing time between each additionfor the alcohol to be evolved and for the temperature of the solution torise above 165. Heating is continued for another 15 minutes, and, afterthe solution is allowed to cool somewhat, 75 cc. of benzene is added.The bright yellow crystalline product is filtered and washed with ether.The yield is 25 grams of w-benzoyl-mnitro acetanilide; M. P. 136137.

Compound 10 is prepared as from compound 12 as follows:

w-Benzoylwcetamino-m-thioylycolic anilide NaOH CoHtCOCHzCONHNHCOOHzSCOCHa OtHsOOCHzGONH NHCOCH2SH To a suspension of 1.85 gram(0.005 mole) of benzoylacetamino m acetylthioglycolic anilide in 5 cc.of alcohol is added cc. of 5 per cent sodium hydroxide (0.0125 mole),and the mixture is stirred until solution is effected. The solution isdiluted to cc., filtered and let stand 10 minutes. The alkaline solutionis kept at room temperature (25 C.) throughout. The product separates asa gum when the solution is acidified with 10 cc. of 10 per cent aceticacid. After washing several times with water, the gum slowlycrystallizes. There is obtained 1.25 grams ofwbenzoylacetamino-m-thioglycolic anilide melting at Mil-149.

Compound 9 is similarly prepared from compound 11.

Compound 15 is prepared by condensing p- (acetoacetamino)-aniline wthacetylthioglycolyl chloride in a manner similar to that used in thepreparation of compound 13.

N02 CaHgOH Compound 6 is prepared as follows:

2- (a-bmmopropionamido) -4,6-d130hlord- 5- methylphenol 01 -NEIz.HCl

. BrOOCHBr 2NaOAc CH HI o1 NHOOOHBr H; NaGl NaBr 2HOAc GHa To a wellstirred suspension of 22.8 grams (0.1 mole) of2-amino-4,6-dichloro-5-methylphenol hydrochloride and 17.5 grams (0.2mole) of anhydrous sodium acetate in 200 cc. of glacial acetic acid wasadded 21.6 grams (0.1 mole) of u-bromopropionyl bromide. The mixture wasstirred at 50 for two hours, and then flooded with water. The oil wasextracted with ether, and the ether layer washed, dried andconcentrated. The. residue Was recrystallized from benzene, M. P. 144-146.

2-a-acetylmercaptoprop'ioncmido) -4,6-dichloro- 5 -me.thylphenol 01NHOO(3HBr cm Ksoocm 0H.-

01- NHCOCHSCOCH;

OH: KBr CH3" To a solution of potassium thioacetate prepared from 0.4gram of thioacetic acid and 0.23 gram of potassium hydroxide in 15 cc.of ethyl alcohol was added 1.6 grams of 2-(a-bromopropionamido)4.6-dichloro-5-methylphen0l. The clear solution warmed to 35 andpotassium bromide separated. After standing overnight, water was addedand the solid collected on a filter. It was recrystallized from dilutedalcohol; M. P. 132- 133,

The preparation of the couplers used according to our invention isdescribed in our divisional U. S. Patent 2,412,700, granted December 17,1946.

The following examples, which are illustrative only, indicate a methodof forming a multi-layer photographic element, using the couplers of ourinvention:

A cyan coupler solution is prepared by dissolving 6.9 grams (0.03 mole)of 2-hydroxy-l-methyl- 5-chloro-thioglycolic anilide in cc. of 2% sodiumhydroxide. A very fine silver chloride emulsion i prepared by awell-known procedure containing 6.4 grams (0.045 mole) of silverchloride in 880 cc. of a 2.3% gel solution. The'cyan coupler solution isadded with rapid stirring to this very fine grain silver chlorideemulsion. This forms a silver salt of the cyan coupler in very finedispersion. This coupler dispersion may then auaoso 9 be mixed with anequalvolume of a higher speed red-sensitized emulsion and coated on asupport, spreading 45 grams of coupler per thousand square feet.

A magenta couplersolution is prepared by dissolving 5.5 grams (-0.02mole) of p-acetylthioglycolylam'inowecyanoacetcphenone in 72 cc. of 2%sodium hydroxide. A very fine grain silver chloride emulsion is preparedby a well-known method containing 4.3 grams (0.03 mole) of silverchloride in 928 cc. of a 1.1% gel solution. The

magenta coupler solution is added with rapid stirring to this very finegrain silver chloride emulsion. This forms a silver salt of the magentacoupler .in very fine dispersion. This .coupler dispersion may then bemixed with one-half the volume of a higher speed green-sensitizedemulsion and coated on the red-sensitized cyan layer spreading 60 gramsof coupler per thousand square feet.

A yellow filter layer is coated .over the red and green-sensitive layersto protect them from the blue light to which they are inherentlysensitive. This filter layer may consist of a very fine dispersion ofsilver prepared by the C'arey-Leadextrin method. It should be coated soit has adensity of 2.0 to light of Wave length 420 me.

The yellow coupler is prepared by dissolving 7.4

.grams of (0.02 mole) of w-benzoylacetamino-pacetylthioglycolic anilidein 80 cc. of 2% sodium hydroxide. A very fine silver chloride emulsionis prepared by a well-known procedure containing 4.3 grams (0.03 mole)of silver chloride in 920 cc. of 1.1% gel solution. The yellow couplersolution is added with rapid stirring to this very fine grain silverchloride emulsion. This forms a silver .salt of the yellow coupler invery fine dispersion. This coupler dispersion may then :be mixed with:one-

veloped directly to "form a negative colored image -or a positive imagemaybe obtained byfirst developing in an ordinary black-and-whitedeveloper followed by color development of the residual silver halide.

The emulsions containing our coupler com- .pounds are developed with anysuitable primary aromatic amino developing agent, such as the solutionsdescribed in Peters-on U. 8. Patents 2,296,306 and 2,353,754.Development is preferably carried out for about 5 minutes at 65 F. afterwhich the element is treated with a weak acid stop bath, suchas aceticacid rollowed by ferricyanide and hy-po baths to remove the silver andanyunde'veloped silver halide which the film co'ntai'ns. These bathsalso remove an unused coupler.

It will be apparent that the emulsion layers made with the couplers ofour invention maybe coated on any suitable support such as cellulosenitrate,'cellulose acetate, glass or synthet-icresins or on opaquesupports, such as paper or pigmented cellulose esters.

The modification and examples included herein are illustrative only :and:it will be understood that 10 ourinvention is to be taken as limitedonly by the scope or the appended claims.

. Weclaim;

1. The method of producing a colored photographic image in a silverhalide emulsion layer which comprises incorporating in said layer ametallic salt of a coupler compound having the formula:

RNH-CO OSX where R" is selected from the class consisting of 2 hydroxymononuclear aryl radicals, 5,-hydroxynaphthyl radicals, l-benzoylacetanilido radicals, acetoacetylanilido radicals, omega-cyanoacetophenone radicals, and 3-(1-phenyl-5-pyrazolone) radicals, R and Rare selected from the class consisting of hydrogen and alkyl groups, andX is selected from the class consisting of hydrogen and acetyl groups,exposing said layer and developing it with a primary aromatic aminodeveloping agent.

2. The method of producing a colored photographic image in a silverhalide emulsion layer which comprises incorporating said layer ametallic salt of a coupler compound having the formula:

where R is a 2-hydroxy mononuclear aryl radical and .R and R areselected from the class consisting of hydrogen and alkyl groups, and Xis selected from the class consisting of hydrogen and acetyl groups,exposing said layer and developing it with a primary aromatic aminodeveloping agent.

3. The method of producing a colored photographic image in a silver,halide emulsion layer which comprises incorporating in said layer ametallic salt of .a coupler compound having the formula:

where R and R are selected from the class consisting of hydrogen andalkyl groups, and X is selectedirom the class consisting of hydrogen andacetyl groups, exposing said layer and developing it with a primaryaromatic amino developing agent.

4. The method of producing a colored photographic image ,in a silverhalide emulsion layer which comprises incorporating in said layer ametallic salt of a coupler compound having the formula: 7

where R and R are selected from the class-consistingoi hydrogen andalk-yl groups, X is elected where R is selected from the classconsistingot '2-hydroxy mononuclear aryl radicals, 5-hydroxynaphthylradicals, l-benzoyl acetanilido radicals, ;.acetoacetylanilido radicals,omega-cyano acetoformula:

phenone radicals, and 3-(l-phenyl-5-pyrazolone) radicals, and X isselected from the class consisting of hydrogen and acetyl groups,exposing said layer and developing it with a primary aromatic aminodeveloping agent. i

6. The method of producing a colored photographic image in a silverhalide emulsion layer which comprises incorporating in said layer ametallic salt of a coupler compound having the where R is a Z-hydroxymononuclear aryl radical and X is selected from the class consisting ofhydrogen and acetyl groups, exposing said layer and developing it with aprimary, aromatic amino developing agent.

.7. The method of producing a colored photographic image in a silverhalide emulsion layer which comprises incorporating in said layer ametallic salt of a coupler compound having the formula:

ONHHO o HZSX where X is selected from the class consisting of hydrogenand acetyl groups, exposing said layer and developing it with a primaryaromatic amino developing agent.

8. The method of producing a colored photo- :graphic image in a silverhalide emulsion layer which comprises incorporating in said layer ametallic salt of a coupler compound having the formula:

Y-CHiC ONH NHO o omsx where X is selected from the class consisting ofhydrogen and acetyl groups, and Y is selected from the class consistingof acyl and cyano groups, exposing said layer and developing it with aprimary aromatic amino developing agent.

9. The method of producing a color-forming photographic emulsion whichcomprises forming 'a sensitive silver salt in a colloidal material andthen incorporating in said materiala metallic salt of a coupler compoundhaving the following formula:

Where R" is selected from the class consisting of 2-hydroxy mononucleararyl radicals, 5-hydroxynaphthyl radicals, l-benzoyl acetanilidoradicals, acetoacetylanilido radicals, omega-cyano acetophenoneradicals, and 3-(1-phenyl-5-pyrazolone) radicals, R and R are selectedfrom the class consisting of hydrogenand alkyl groups, and X is selectedfrom the class consisting of hydrogen and acetyl groups, exposing saidlayer and developing it with a primary aromatic amino developing agent,and forming a metallic salt of said coupler compound less soluble thansaid sensitive silver salt by replacement of the X substituent of saidcoupler compound with a metallic atom.

10. The method of producing a color-forming photographic emulsion whichcomprises forming a sensitive silver salt in gelatin .and then in-.corporating in said gelatin a metallic salt of a coupler compoundhaving the following formula: R '-NHCOCH2SX where R" is selected fromthe class consisting of '2hydroxy' mononuclear aryl radicals,5-hydroxywhere R" is a 2-hydroxy mononuclear aryl radical and X isselected from the class consisting of .hydrogen and acetyl groups, andforming a silver salt of said coupler compound less soluble than saidsensitive silver salt by replacement of the Xsubstituent of said couplercompound with a silver atom.

12. The method of producing a color-forming photographic emulsion whichcomprises forming a sensitive silver salt in gelatin and thenincorporating in said gelatin a metallic, salt of a coupler compoundhaving the following formula:

ONHC oomsx where X is selected from the class consisting of hydrogen andacetylgroups, and forming a silver salt of said coupler compound lesssoluble than said sensitive silver salt. by replacement of the X'substituent of said coupler compound with a silver atom.

13. The method of producing a color-forming photographic emulsion whichcomprises forming 'a sensitive silver salt in gelatin and thenincorporating in said gelatin a metallic salt of a coupler compoundhaving the following formula:

v o 0 onto ONH-QNHO oomsx.

where X is selected from the class consisting of hydrogen and acetylgroups and forming a silver salt of said coupler compound less solublethan said sensitive silver salt by replacement of the X substituent ofsaid coupler compound with a silver atom.

14. A gelatino-silver halide emulsion for color photography containing anon-diffusing colorforming compound having the following formula:

RI I E ma-00 0 :91

where R. is selected from the class consisting of '2-hydroxy mononucleararyl radicals, 5-hydroXynaphthyl radicals, l-benzoyl acetanilidoradicals,

acetoacetylanilido radicals, omega-cyano acetophenone radicals, and3-(1-phenyl-5-pyrazolone) radicals, R and R are selected from the classconsisting of hydrogen and alkyl groups, and M is a heavy metal radical.

15. A gelatino-silver halide emulsion for color photography containing anon-diffusing colorforming compound having the following formula:

13 Where R" is a 2-hydroxy mononuclear aryl radical and where R and Rare selected from the class consisting of hydrogen and alkyl groups, andM is a heavy metal radical.

16. A gelatino-silver halide emulsion for color photography containing anon-diffusing colorforming compound having the following formula:

OH R,

where R and R are selected from the class consisting of hydrogen andalkyl groups, and M is a heavy metal radical.

17. A gelatino-silver halide emulsion for color photography containing anon-diffusing colorforming compound having the following formula:

Y-omo ONHONH 0 0 s! where R and R are selected from the class consistingof hydrogen and alkyl groups, and Y is selected from the classconsisting of acyl and cyano groups. and M is a heavy metal radical.

18. A gelatino-silver halide emulsion for color photography containing anon-diffusing colorforming compound having the following formula:

where M is a heavy metal radical.

19. A gelatino-silver halide emulsion for color photography containinga. non-diffusing colorforming compound having the following formula:

O00 0112c ONHGNHO o omsM 5 where M is a heavy metal radical.

ARNOLD WEISSBERGER. CHARLES J. KIBLER. RICHARD V. YOUNG.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,673,522 Matthels et a! June 12,1928 1,971,409 Henle et a1. Aug. 28, 1934 2,062,614 Schmelzer Dec. 1,1936 2,066,099 Dieterle Dec. 29, 1936 2,186,733 Schneider Jan. 9, 19402,193,678 Muth Mar. 12, 1940 2,235,426 Goodman Mar. 18, 1941 2,269,147Dickey et al. Jan. 6, 1942 2,279,411 Peterson Apr. 14, 1942 2,295,008Porter et a1. Sept. 8, 1942 2,296,306 Peterson Sept. 22, 1942 2,298,443Weissberger Oct. 13, 1942 2,308,023 Peterson Jan. 12, 1943 2,353,754Peterson July 18, 1944 2,387,145 Gluck -1 Oct. 16, 1945 2,401,718 YoungJune 4, 1946 FOREIGN PATENTS Number Country Date 390,037 Great BritainMar. 30, 1933 Certificate of Correction Patent No. 2,448,939. September7, i948.

ARNOLD WEISSBERGER ET AL.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Column 11,line 25, claim 7, in the formula, for NHHOCH SX read NHCOUH SX; and thatthe said Letters Patent should be read with this correction therein thatthe same may conform to the record of the case in the Patent Office.

Signed and sealed this 16th day of November, A. D. 1948.

THOMAS F. MURPHY,

Assistant Commissioner of Patients.

